An advertisement placement system is used to select and display advertisements that are contextually related to a specific dataset, such as one or more documents, e-mail messages, RSS feeds, or web pages, that is being viewed or manipulated by a user. One type of system, such as SmartAd by Vibrant Media and early versions of Quigo AdSonar, uses a keyword method to place contextually related advertisements on web pages. According to the keyword method, each advertisement is assigned a small number of keywords. When an advertisement request is received, the system compares the keywords associated with the web page with keywords on each advertisement, and determines whether an advertisement is appropriate based on whether all or some of its keywords match the web page keywords. This type of advertisement placement system has several disadvantages. First, the number of keywords retained from a document is typically restricted for reasons of runtime efficiency, leading to a poor representation of the document. If a manual selection of keywords is involved, the process is extremely labor-intensive. Furthermore, an advertisement may mistakenly match a non-relevant document if the advertisement and the document share a keyword that has different meanings in the contexts. Such an approach also will miss an advertisement that is contextually related to a document but does not have an exact match in the keywords.
Other types of advertisement placement systems, such Kanoodle ContextTarget, use category methods to find advertisements related to a web page. In the category method, each advertisement is assigned to one or more categories. Each of a plurality of web pages is assigned to one or more categories. When an advertisement request is received for a web page, the system determines the corresponding category or categories of the web page and retrieves any or all advertisements in the same category or categories.
Category methods have several drawbacks. First, if a manual assignment of categories is involved, the process is prohibitively expensive and tedious. Further, even with automatic category assignments the category methods do not provide precise matches between web pages and advertisements because all advertisements and web pages within a category are typically considered equally good matches, limiting match relevance to a fairly coarse granularity. In addition, the category methods have difficulty handling advertisements or web pages that do not fall cleanly into a single category, either because the advertisement or web page spans multiple topics, or because the advertisement or web page is about a topic that does not have a clear correspondence in the category scheme.
A system called Quigo AdSonar Exchange tries to combine the keyword and category methods, in which it first assigns each web page and advertisement into one of several broad categories, and then performs keyword matching within that category. However, such an approach still shares some or all disadvantages of the keyword and category methods.
Accordingly, there is a need for a method and system to effectively determine contextual relevance between an advertisement and a dataset. In addition, there is a need for an advertisement placement method and system that effectively select one or more advertisements that are contextually relevant to a dataset.